Polymer compositions suitable for use in enriched oxygen atmospheres

Three organic polymer systems are based on copolymer of chlorotrifluoroethylene, ethylene, and tin-based flame retardants. Fourth system is copolymer of chlorotrifluorethylene and tetrafluoroethylene. This system contains no stabilizers of flame retardant additives

Asymptotic Charges Cannot Be Measured in Finite Time

To study quantum gravity in asymptotically flat spacetimes, one would like to understand the algebra of observables at null infinity. Here we show that the Bondi mass cannot be observed in finite retarded time, and so is not contained in the algebra on any finite portion of ${\mathscr{I}}^+$. This follows immediately from recently discovered asymptotic entropy bounds. We verify this explicitly, and we find that attempts to measure a conserved charge at arbitrarily large radius in fixed retarded time are thwarted by quantum fluctuations. We comment on the implications of our results to flat space holography and the BMS charges at ${\mathscr{I}}^+$.Comment: 9 pages, 3 figures. v2 typos fixed and minor addition

Distance Cautious IP - A Systematic Approach in VANETS

VANET is a decentralized network that allows the vehicles to communicate with each other for providingsafety warning, traffic management and driver assistance systems. Vehicular IP in Wireless Access in Vehicular Environments (VIP-WAVE)has characterized the IP configuration for extended andnon-extended IP services, and amobilitymanagement scheme supportedby Proxy Mobile IPv6 over WAVE.As the vehicular networks are formed even in remote areas with inadequate power source, the units have power constraints which are overcome by power control in the proposed system .The objective of the paper is to improve the quality of the network by providing internet accesswith transmit power control along which the distance between the RSU and on-board vehicular units(OBU)is determined i.e., power consumption is reduced when at least distance. Hence the RSU provides Distance Cautious Internet Protocol (DCIP) to the OBU for internet access.This paper analyses the WAVE standard and its support of IP based applications, and proposesDistance Cautious Internet Protocol in WAVE(DCIP-WAVE)

What is the right temperature to cool post-cardiac arrest patients?

Background: Brain ischemia and reperfusion injury leading to tissue degeneration and loss of neurological function following return of spontaneous circulation after cardiac arrest (CA) is a well-known entity. Two landmark trials in 2002 showed improved survival and neurological outcome of comatose survivors of out-of-hospital cardiac arrest (OHCA) of presumed cardiac origin when the patients were subjected to therapeutic hypothermia of 32 to 34°C for 12 to 24hours. However, the optimal target temperature for these cohorts is yet to be established and also it is not clear whether strict fever management and maintaining near normal body temperature are alone sufficient to improve the outcome. Methods: Objective: The objective is to determine whether a hypothermic goal of a near-normal body temperature of 36°C reduces all-cause mortality compared with a moderate hypothermia of 33°C for the unconscious survivors of OHCA of presumed cardiac origin when subjected randomly to these different targeted temperatures. Design: A multicenter, international, open label, randomized controlled trial. Setting: Thirty-six ICUs in Europe and Australia participated in this study. Participants: Unconscious adults (older than 18years of age) who survived (Glasgow coma scale less than 8) OHCA due to presumed cardiac origin with subsequent persistent return of spontaneous circulation (more than 20minutes without chest compressions). Intervention: The above participant cohorts were randomized to targeted body temperature of either 33°C or 36°C for 36hours after the CA with gradual rewarming of both groups to 37°C (hourly increments of 0.5°C) after the initial 28hours. Body temperatures in both the groups were then maintained below 37.5°C for 72hours after the initial 36hours. Outcomes: Primary outcome measure of all-cause mortality in both the groups at the end of the trial with the secondary outcome measure of all-cause mortality, composite neurological function as evaluated by cerebral performance category scale and modified ranking scale at the end of 180days were studied. Results: Out of the 939 participants, all-cause mortality at the end of the trial was 50% in the 33°C group (225 of 466 patients) compared with 48% in the 36°C group (235 of 473 patients); the hazard ratio with a temperature of 33°C was 1.06 (95% confidence interval (CI) 0.89 to 1.28, P = 0.51). At the end of 180days, 54% of patients in the 33°C group versus 52% in the 36°C group had died or had poor neurological outcome according to cerebral performance category (risk ratio 1.02, 95% CI 0.88 to 1.16, P = 0.78) but the modified ranking scale at the end of 180days was unchanged (52%) in both groups (risk ratio 1.01, 95% CI 0.89 to 1.14, P = 0.87). Conclusions: Maintaining targeted lower normothermia of 36°C had similar outcomes compared with induced moderate hypothermia of 33°C for unconscious survivors of OHCA of presumed cardiac cause

Diagonal and Low-Rank Matrix Decompositions, Correlation Matrices, and Ellipsoid Fitting

In this paper we establish links between, and new results for, three problems that are not usually considered together. The first is a matrix decomposition problem that arises in areas such as statistical modeling and signal processing: given a matrix $X$ formed as the sum of an unknown diagonal matrix and an unknown low rank positive semidefinite matrix, decompose $X$ into these constituents. The second problem we consider is to determine the facial structure of the set of correlation matrices, a convex set also known as the elliptope. This convex body, and particularly its facial structure, plays a role in applications from combinatorial optimization to mathematical finance. The third problem is a basic geometric question: given points $v_1,v_2,...,v_n\in \R^k$ (where $n > k$) determine whether there is a centered ellipsoid passing \emph{exactly} through all of the points. We show that in a precise sense these three problems are equivalent. Furthermore we establish a simple sufficient condition on a subspace $U$ that ensures any positive semidefinite matrix $L$ with column space $U$ can be recovered from $D+L$ for any diagonal matrix $D$ using a convex optimization-based heuristic known as minimum trace factor analysis. This result leads to a new understanding of the structure of rank-deficient correlation matrices and a simple condition on a set of points that ensures there is a centered ellipsoid passing through them.Comment: 20 page

Nearly Optimal Private Convolution

We study computing the convolution of a private input $x$ with a public input $h$, while satisfying the guarantees of $(\epsilon, \delta)$-differential privacy. Convolution is a fundamental operation, intimately related to Fourier Transforms. In our setting, the private input may represent a time series of sensitive events or a histogram of a database of confidential personal information. Convolution then captures important primitives including linear filtering, which is an essential tool in time series analysis, and aggregation queries on projections of the data. We give a nearly optimal algorithm for computing convolutions while satisfying $(\epsilon, \delta)$-differential privacy. Surprisingly, we follow the simple strategy of adding independent Laplacian noise to each Fourier coefficient and bounding the privacy loss using the composition theorem of Dwork, Rothblum, and Vadhan. We derive a closed form expression for the optimal noise to add to each Fourier coefficient using convex programming duality. Our algorithm is very efficient -- it is essentially no more computationally expensive than a Fast Fourier Transform. To prove near optimality, we use the recent discrepancy lowerbounds of Muthukrishnan and Nikolov and derive a spectral lower bound using a characterization of discrepancy in terms of determinants